Furnace



July 11, 1939. E. q. BYZAILEY FURNACE Original Filed July 10, 1934 3 Sheets-Sheet 1 INYENTOR Q Erwn G. Bailey A ORNEY Jul 11511 939 E. e. BAILEY 2,155,207

FURNACE Original Filed July 10, 19:41 3 sheets-sh ez'sa Fig 4 '!NVE NTOR Erwin 6: Bailey A ORNEY July 11, 1939. G B EY 2,165,201

FURNACE Original Filed July 10, 1934 3 Sheets-Sheet 3 mENTOR.

' Ervin G.Bai1e y EiriR-p W ATTORNEY.

limits the; temperature rise of the metal surfaces over the temperature of the contained cooling Patented Jul 11, 1939 UNITED STATES PATENT OFFICE FURNACE Applica'tion July 10, 1934, Serial No. 734,456 Renewed February 20, 1937 '16 Claims. (Cl. 122-235) This invention relates to improvements in fluid heat exchange apparatus, and more particularly to improvements in furnaces which have combus- .tion chamber walls cooled by fluid circulating in tubes in the walls. y

In the construction and operation of furnaces having fluid cooled walls it is advantageous to employ rows of fluid conducting tubes as the structural strength'members of the combustion chamber wall, and such tubes are used in this way in the practice of the present invention. Excessive cooling of the combustion gases is prevented by the maintenance of refractory material upon the furnace sides of the tubes. furnace face of this refractory material is heated to high temperatures it promotes adequate combustion within the furnace; and simultaneously To promote adequate heat transfer from the refractory facing to the fluid conveyed by the tubes of the furnace wall, the furnace sides of the tubes are provided withwelded metallic extensions suitably spaced and ofadequate heat conducting cross-section. These extensions bond -the refractory lining and have the function of mechanically as well as thermally maintaining, the refractory facing'upon the fluid cooled metallic surfaces.

The furnace included in the present invention is of such a character that-it has different parts of its walls formed by rows of spaced tubes. The corresponding ends of the rows of tubes are'connected by chambers such as headers or drums. One set of tubes may be connected to a drum whereas another set of tubes forming another part of the furnace wall may be connected to a header and the header may be adjacent the drum. In many instances, it is not feasible to locate headers or drums in positions spaced mate.- rially from or outside of the furnace wall, and. in fact, in many cases in the construction of boilers, itis of particular advantage to locate the drums or headers in such positions that the furnace wall tubes extending therefrom are exposed to heat from the furnace gases over their entire lengths. A bottomsupported water tube wall is an important example. This invention provides a combination which permits the drums or headers to be located in the last mentioned position with-,- out the sacrifice of operating advantages.- r

Another object of the present invention is to When the ameliorate conditions which tend to produce tube as seat leakage by providing the region of the junctions of the tubes with the headers vor drums with a. heat resistant permanent facing which may be economically applied and maintained,

and which may at the same time serveQto raise furnace temperatures above values that would exist without such facing.

It is specifically within the purview of the invention that the steam generating tubes of ,a boiler, and an associated boiler drum (or equivalent fluid chamber) may be so modified that they act as fluid cooled walls and have the advanta geous operating characteristics of the latter, and

the invention'may be applied to existing boilers Fig. 2 is a detail section showing tubular fluid heating. members to which welded metallic studs and a refractory facing are applied. This view v is on'the line 2-2 of Fig. 1. Fig. 3 is a transverse section through a portio of a furnace wall including tubes with diametri- 'cally opposite longitudinal flanges or m to which the welded studs and refractory facing areapplied.v l v Fig. 4 is a vertical section of a part of a furnace construction having a water tube hopper bottom inclined on two sides, the other two sides having straight water tubes ending in bottom headers.

' Fig. 5 is a vertical section on the line'S-J! of Fig.4. Fig. 6 is a section of a part of the construction indicated'in Fig. 5, made on a muchslarger scala. Fig. 'l is a transverse section of the boiler,

shown in Fig. I placed over a furnace. 1

Referring to Figure 1 of the drawings the tubes l6 are boiler tubes which are preferably arranged so that they are exposed to the fire of an adjacent furnace. These tubes are expanded in a drum ii at their lower ends, one side of the drum facing'the furnace. The sides of the tubes toward the flre have the spaced metallit studs 5 welded thereto. The refractory material 8 is .indicated as embedding the studs and extending over the tubes so as to constitute a wall interposed between the furnace and the'tu'bes so that the furnace is made hotter than itotherwise would be. Similar studs 5' are spaced overthe furnace side of the l5 and weldedther eto,

and the refractory material C extends past the u Thefacipgon dnunalao-contrilmtestothe raisingotthefurnaeetemperaturewbiiethefactubs and drum promote: equalin- Spaeedfromthedrmnliiatheheaderli connectedtotubes llwhichextendalonga wallofthefurnace. Asshowmtbeheaderflis a water wall header preferably in connection withtheboiler circulation. Intheparent application 39,010, this header and its associated atructlnu in the following lanm rm. '1 and 8 (Figs. 1, 2 and a of thepresent -structionwhichareexposedmoredirectlytliau the ml: to the actionof the most intense flame audheatfromthefire, and-whichin consequence stiilremainingoodcondition.

Asanexampleofsuchportionsoftheboilera I transverse manifold is indicated at 12, a transveroewltercontainerormuddrmnatliauda Janl; ofciruilaflngtubes It, which exte'ndupshown) themumehaam-mmuyfle st llsflweldedto theheader.

-m-mnnmuwemne.siioauu hadhnhflmiwhieharepositionedat callymultepartadthetubaauduealianed in m o-nuatou rmoruemmeenu. 4

ofthetulieewitlrthechaining.

taboilerfumacemrowotspaeedfluideooled" tubsamasid'eofthefmmeeanterdiam lu ai-- diametri- 2 2,105,907 tubestoalsocoverthefumacesideofthe drum.

Welded proiccflons SI inthe form-of ribs or stud: extend-into a refractory facing preventing thn endsofflnsfrombeingbumedasweliascompleting the space closm'e between tubes;

when the tubes with their welded metal projections are not covered by refractory or haw only a cmnparatively thin covering of reiracton materiabslagfromashinthefuelwilibefusec when the furnace is operated at a high rate, 7811C: will acclunulate on the projections which arr prevented from excessive binning by the resultant coolingeifect of the fluid within the tubes Thus the ash itself may form a suitable coating upon the tubes to produce the temperature conv ditions requiredinthefurnace and in the meta 4 duetlvity to avoid exemive diiferences between theirflpeandthelrboseaandtoprotectthe-refractm'yfpomoverheatingasweiiastomeehanieally-hdd it, and I have found'velectric welding tobeaaaflsfactor'ywayof'thermallybondingthe projections to the fluid cooled tube header or While the invmflon has-been described with reference to certain particular embodiments it is tcbeunderstoodthatit isnot limited thereto. hutfliatitis'ofa'scope commensurate withthe no ammon a a continuation-in-part of m application Serial 39,01 1116!! 1. In'flubiheatemfllangeapparatuaamrnace, aiinidehambcintheformofaheaderordnun extmdinghaunenelyof-awallofthe furnace inmouimibthereto and exposed to heat from withtbe chambei'uuiextmdine-alongasldeofthefurofthctubesandthechamber'facingjheinterior M extending overlaid around 1.2. aiiuidchamberextendiuxtransversely' ofawali.

or thefurnace and expand. to a flint the furnace, metallic aidesofthetubes thechamberfaclngthe interior ofthefurddesaaalayerandextmdingoyertheilmcflons nectedto hatfnnn slag layer deposited by the products of combusrigid refractory material applied in non-rigid condition over the faces of the header and the tubes having the metal members thereon, said refractory material forming a shield covering the junctions of the tubes and the chamber wall.

4. In a-furnace, means for burning fuel in the furnace, spaced fluid conducting tubes, a drum forming a connection for the tubes, metallic studs distributed over the sides of the tubes and the drum facing burning fuel in the furnace, a water wall header adjacent the drum, studs welded to the header, a refractory layer positioned between the projections and extending over the furnace sides of-the drum and header to form a gas boundary wall connecting them.

. 5. In fluid heat exchange apparatus having parts exposed to the heat of a furnace and coma rigid refractory layer positioned .over the furnace faces of the tubes and the chamber while in a non-rigid condition, the projections acting to control the heat exchange and prevent excessive erosion of the refractoryby cooling the refractory.

6. Fluid heat exchange apparatus acting as a part of a furnace andcomprising, in combination, an inner structure consisting of a, row of aligned tubes and a connected drum conducting a fluid past a heating zone wherein the fluid receives heat transmitted from burning fuel through the tube and drum walls; and an outer composite structure including metallic projections welded to the tubes and the drum, and a tion moving from the burning fuel and extending across the tubes and the drum and embedding the projections to forma shield between the drum 7 and the tubes and the burning fuel, the projections acting as supports or anchors for holding the deposited slag layer in operative position, said row of tubes absorbing a preponderance of heat on one side of the row.

7. In a tubular heat exchanger exposed to heat from a furnace to transmit to a contained fluid the heat received radiantly from fuel burning in members projecting from and welded to the the furnace; said tubular heat exchanger having a metallic inner structure consisting of the walls of tubes and a'fluid chamber connected to the tubes, said walls, being in contact with the contained fluid; and a composite outer structure exto radiant heat from the burning fuel; said outer structure comprising metallic extensions extending outwardly from and welded to the tubesand a wall of the chamber, and refractory materials contacting with the inner part and located between the extensions, said refractory materials extending over said walls and being of greater thermal resistance than the material of the remaining structure, thereby preventing overheating of the exchanger metal and contributing to higher-furnace temperatures.

8. A furnace wall having a horizontally arranged header, metallic refractory retaining furnace side of said header, and refractory at the furnace side of said header covering and-held on said'header by said retaining members.

9. In a tubular heat'exchanger adapted as a part of a steam boiler and-its furnace to transmit to a contained fluid the heat received radiantly from fuel burning in the furnace; said tubular heat exchanger having a row of spaced tubes extending across the path of furnace gases and constituting a metallic inner structure in contact with the contained fluid and including metallic means forming a pressure chamber in the form of a header or drum communicating with the tubes; and a composite outer structure exposed to radiant heat from the burning fuel; said outer structurecomprising metallic projections extending outwardly from the tubes and the drum or header of the inner structure and rigidly connected therewith, with the projections on at least some of the tubes independent'of the projections on others ofv the tubes, and refractory material contacting with the inner structure and located between the projections; said refractory material being of greater thermal resistance than the material of the remaining structure to thereby prevent overheating of the exchanger metal and contribute to higher furnace temperatures.

10. In a tubular heat exchanger adapted as a part of a steam boiler and its furnace to transmit to a contained fluid the heat-received radiantly from fuel burning in the furnace; 'said tubular heat exchanger having an inner part consisting of, a row of steam generating tubes and 'means forming a lower water chamber communicating with said tubes; and a composite outer structure exposed to radiant heat from the burning fuel;

tions extending outwardly from the tubes and water chamber of the inner part toward the burning fuel and rigidly connected with the inner part, with the projections ori at least some of the tubes independent oft-he projections on others of the tubes, and refractory material contacting with the inner part and located between the projections; said refractory'material being of greater thermal resistance than the material of the remaining structure to thereby prevent overheating of the exchanger metal and contribute to higher furnace temperatures.

. 11. In a tubular heat exchanger adapted as a part of a steam boiler and its furnace to transmit I to a contained fluid the heat received radiantly from fuel burning in 'thefurnace; said tubular heat exchanger having a row of spaced tubes part toward the burning fueland rigidly connected with the inner part, with the projections on at least some of the tubes independent of the projections on others of-the tubes, and refractory material contacting with the inner part and located between the projections; said .refractory material being of greater thermal resistance than the material of the remaining said'outer structure comprising metallic 'projecstructure to thereby prevent overheating of the refractory facings beingfldeflnitel'y spaced, apart to allow furnace gases to pass between them.

12; In a tubular heatexchanger adapted as a g' part of a steam boiler and its furnace to transmit part ofa steam boiler audits furnace to mit to it contained fluid theheat received radiantly from fuel burning in the furnace; said tubular heat exchanger having a row of tubes extending across the path of the furnace gases constituting a metallic inner structure in contact with the contained fluid; means for connecting said tubes into a fluid circulation; means for burning a slug forming fuelin the furnace so that the furnace gases pas's between said tubes and deposit thereon combustion solids carried in suspension before the gases contact with other disposed fluid heat exchange surface;

and a composite outer structure exposed to radiant heat from theburning fuel; said outerstructure comprising metallic projections extending outwardly from the inner structure and rigidly connected therewith, with the projections on at least some of the tubes independent of the projec tions on others of the tubes, and refractory material contacting with the inner structure and located between the projections, said refractory material being of greater thermal resistance than the material of the remaining structure to thereby prevent overheating of the exchanger metal and contribute to higher furnace temperatures; the tubes and their refractory facings being definitely spaced apart to allow furnace gases to pass between them.

13. In a tubular heat. exchanger adapted as a to a contained fluid the heat received radiantly from fuel burning in the furnace; means forming a lower water chamber; means forming an 7 upper steam and water chamber, means for from the inner structurejand rigidly connected tactwithaconj 1 therewith, with projections. on at least some of the. tubes independent of the projections on oth- V ers-of thetubes, and refractory material conwlth the inner structm'e and located be tween the projections, said refractory material being of greater than the materlal of the remaining structuretothereby pre.-

vent ov of the exchanger metal and 0011'? tributetohigherfurnacetemperaturesthetubes and fa'cings being. definitely spacedaparttoallowfurnacegasestopassbe- 14. In a,v tublflar heat exchanger adaptedto "transmit to a contained fluid theheat received. from furnace gases and having anei'fectlve length positioned entir'eiy'wlthin -"a furnace gas space;

'said tubular heat includinggspaced units each having con- "fluid; and a out-' 12,105,297 I g g 4 transer structure adapted to beexposed directly to furnace gases which pass on substantially all sides thereof; said outer structure cmnprising metallic projections extending outwardly from the inner part and rigidly connected therewith, and

refractory materialcontacting with the inner part and located between the projections; said refractory material being of greater thermal re-' sistance than the material of the structure to thereby prevent overheating of the inner part, and a partof the' metal oftheunitv being bare in a zone extending-longitudinally of the unit and defined at opp te sides by the refractory material. 15. ,In tubular fluid heat exchange devices adapted asparts of asteam boiler and it's fur nacetotransmittoacontainedfluidtheheatreceived radiantly from fuel burning in the fur.-

pace; said devices including a of 7 tubes the front tubes of which constitute metallic inner parts in contact with the contained the bank of tubes being contacted and-enveloped by furnace gases passing through and across the bank; and composite outer structures exposed on the front sides of the front tubes of said bank directly to radiant heat from the hurningfuel; said outer structures including metallic projections extending outwardly from thejnner parts toward the burning fuel and rigidly connected with the inner'parts with-the projections on the individual tubes independent of the projections on other tubes, and refractory material contacting the inner parts and located between the pro:

; jections; said refractory material being of greater thermal resistancethan the material of the re- {s maining structure to, thereby increase thecapacity and operative life of the boiler. prevent overheating of exchanger metal, and contribute :tohigher furnace temperatures; the tubesand their refractory facings being definitely gm apart to allow them. A

16, In tubular fluid heat exchange apparatus adapted to transmit to a contained fluid-thehe'at furnace gases to pass received from furnace gases; said apparatusineluding spaced tulps enveloped by the furnace gases and constituting metallic inner parts-in contactwith the contained fluid: and composite outer structures directly exposed on ing sides of the tubes to the furnace gases: said outer structures including metallic 920m? extending outwardly from the inner partstoward the-furnace gases and rigidlyconnectedto inner with the-projections on different tubes independent of each other, and refractory materialjljcontacting with the inner nf-ts and 10-; -cate'tilroetween the projections; said-refractory materialbeingofgreaterthermalthan the material of the remaining structure to-fliereby prevent overheating'of the Mil y and contribute to higherfurnace of the tubes opposite the outer structures,

f'tubes and their refractoryfacingabeing definitely spaced apart to allow fm'nace them. 

